Hey ! Yes , I agree with what you said , the 'hook' is what we try to leave as a main melody to the listeners , what we wish they could just hum away all day long haha . And of course ''space'' is a very big element to a song , I've heard a lot of productions in where the elements can be distracting , like for example the 'talented' guitar player as you mentioned just filling in unnecessary sounds. A good producer/arranger will try to keep the song as effective as possible and let it flow organically , just my opinion. Thanks for commenting!
RE: Music Arranging - A small introduction : ''The Importance of a Melody''